- ARTICLE ON FOWL TYPHOID-Dr. Amit Ranjan
- Sub-Clinical Enteric Disorders - Gut Modulation Approach Neospark
- Influence of MCFA’s on zootechnical performances of broilers
- Avian Diseases Transmissible to Humans
- The effective control of Salmonella in poultry by means of diformates
- Coccidiosis in Poultry: An Overview K. Dhama1, M. S. Basaraddi2, Ruchi Tiwari3 and S. B. Shantaveer3
- Parasitic Protozoa: Commercial Vaccines and Vaccination trials
- Surveillance and Monitoring Plan for H5N1 Avian Influenza in Wild Migratory Birds
- Vaccination against Parasitic Protozoa: Recent Trends and Achievements
- Novel and Emerging Therapeutics : Perspectives for Combating Poultry Diseases
- Saturday, 28 July 2012
Address for Correspondence:
Amit Ranjan, Ph. D. Scholar
Department of Animal Nutrition, Faculty of Veterinary and Animal Science, WBUAFS, Belgachia Road, Kolkata, West Bangal (INDIA).
FOWL TYPHOID IN POULTRY
The name Bacillus gallinarum was applied to an organism isolated from outbreak in England firstly considered to be Fowl cholera and reported as "infectious enteritis" (Klein, 1889). Moore (1895) described the disease as "infectious leukemia" and named the organism "Bacillus sanguinarum". Curtice (1902) studied the disease in Rhod Island and named it "Fowl typhoid". Fowl typhoid disease is diseases of worldwide significance. They are of particular economic importance in parts of the world that are beginning to intensify their poultry industry. The diseases have largely been eradicated from many countries that have had a poultry industry from many years. Fowl typhoid is an economically important disease of poultry and other birds, with high mortality in young birds. Hens may become chronic carriers and pass the disease to their embryos by egg transmission.
Fowl typhoid results from infection by Salmonella gallinarum. Chickens are the natural hosts for S. gallinarum; however, the disease can also affect turkeys, ducks, quail, guinea fowl, pheasants, pigeons and geese. Outbreaks have also been described in parrots, sparrows, ostriches, peafowl, and ring-necked doves, and cases have been seen in canaries and budgerigars.
S. gallinarum is transmitted by both the respiratory and oral routes. Apart from this, S. gallinarum can be transmitted by infected (carrier) breeder hens through ovarian transmission via their eggs and produces lesions in chicks and poults. Chicks that hatch from such infected eggs will have high mortality. Fowl typhoid is more a disease of adult chickens, characterized by rapid spread with high morbidity and acute or sub-acute mortality. Horizontal transmission is important with fowl typhoid through infected droppings, dead bird carcasses and attendants, feed dealers, chicken buyers and visitors who move from house to house and from farm to farm may carry infection unless precautions are taken to disinfect footwear, hands and clothing. Similarly, trucks, crates, utensils and feed sacks may also be contaminated. Wild birds, game birds, ‘backyard’ poultry flocks, mammals and flies may be important mechanical spreaders of the organisms. The incubation period is usually 4 to 6 days.
In chicks and poults, the clinical signs of fowl typhoid can include depression, loss of appetite, droopy wings, huddling, dehydration, thirst, ruffled feathers and weakness. Yellow or green diarrhea causing pasted cloaca with adherence of faeces to the vent is common. Birds that survive may be underweight and poorly feathered and may not mature into productive adults. In infected breeding flocks reduced in egg production or fertility and hatchability, poor quality in chicks hatched from infected eggs may be the only signs.
Post mortem lesions
In young birds, the post–mortem lesions can include enteritis, dehydration and anemia. The liver may be swollen, friable and bile stained and may contain white necrotic foci. The spleen is often enlarged and mottled and the kidneys may be enlarged. Petechial hemorrhages can sometimes be found in the fat and musculature surrounding the internal organs, and the peritoneum, pericardium and capsule of the liver may contain a fibrinous exudate. In adult birds, the gross lesions may be minimal. In some animals, there may be a mottled pancreas, excess pericardial fluid, fibrinous pericarditis or caseous granulomas in the lungs and air sacs. The testes sometimes contain white foci or nodules. Chronic carrier hens may have nodular or regressing or dark coloured ovarian follicles or a few misshapen ova among normal ovules. In hens, caseous material is often found in the oviduct, and peritonitis, perihepatitis, or ascites may be seen.
Morbidity and mortality
Morbidity and mortality vary with the species, age, and breed of the birds, nutrition and management and concurrent infections. Ducks, geese, and pigeons are relatively resistant to fowl typhoid. Among chickens, the White Leghorn breed appears to be more resistant. The mortality rate can range from less than 1% to 100%; morbidity is usually somewhat higher. Mortality is usually highest in checks and poults, particularly in two to three–week old birds.
Treatment and control
Control the disease by elimination of infected carrier breeder hens. The test used in the field is the rapid whole blood plate agglutination test and in the laboratory a serum agglutination test is used, either as a rapid plate test or as a tube test to detect infected carrier birds which can then be culled. Such control measures will stop the incidence of egg-transmitted typhoid disease. If hatching eggs from tested typhoid-free breeders are kept free from contamination through infected eggs from infected breeders or through contaminated equipment, chickens can remain after treatment. The best control method is eradication of infected birds.
Immunization of breeding stock with vaccines (killed or modified live) made from a rough strain of S. gallinarum (9R) can prevent infection and reduce the incidence of vertical transmission and useful in controlling mortality, still possesses some virulence for some breeds of chicken and protection is adequate only for up to 6 months so it should be discouraged in breeders when an eradication programme is in operation. Incorporation of antibiotics, such as furazolidone, in the feed can prevent mortality and reduce the carrier rate. S. gallinarum can be inactivated by direct exposure to sunlight, heat treatment, phenol, formalin, dichloride of mercury, or potassium permanganate. Compounds that contain phenol are the most effective disinfectants under field conditions, but quaternary ammonium compounds and iodophores are also effective.
Curtice, C. (1902). Fowl typhoid. Bulletin (Rhode Island. College of Agriculture and Mechanic Arts. Agricultural Experiment Station). Volumes 82-101. Agricultural Experiment Station of the Rhode Island College of Agriculture and Mechanic Arts
Moore, V.A. (1895). Infectious leukemia in fowls. Twelfth and Thirteenth Annual Reports, Bur. An. Ind., U.S. Dept. Agr., I85-205. Smith, Th. 1894. Cited by Moore.
1Amit Ranjan, Ph.D. Scholar
Department of Animal Nutrition, Faculty of Veterinary and Animal Science, WBUAFS, Belgachia Road, Kolkata, West Bangal (INDIA). Pin-700 037
2Divya Kumari, M.V.Sc. Scholar
Department of Veterinary Pathology, Lala Lajpat Ray University of Veterinary and Animal Science, Hisar, Haryana (INDIA). Pin-125 001